Sheet feeding apparatus



p 15, 1964 A. s. CHANDLER ET AL, 3,148,876

SHEET FEEDING APPARATUS 4 Sheets-Sheet 1 Filed Aug. 24, 1962 INVENTOR.AUSTIN S. CHANDLER RAYMOND A. LABOMBARDE BY v-PAW ATTORNEYS P 1 A. s.CHANDLER ETAL 3,148,876

SHEET FEEDING APPARATUS Filed Aug. 24, 1962 4 Sheets-Sheet 2 INVENTOR.AUSTIN S. CHANDLER gA YMOND A. LABOMBARDE W+72ww m g; ATTORNEYS Sept1964 A. s. CHANDLER ETAL 3,148,876

SHEET FEEDING APPARATUS Filed Aug. 24, 1962 4 Sheets-Sheet 3 "8 Fig. 3o(6 H4 l2l\ Ks,

INVENTOR. AUSTIN S. CHANDLE BlgAYMOND A. LABOMB DE Peru Mu;

ATTORNEYS Sept. 15, 1964 A. s. CHANDLER ET AL 3,148,876

SHEET FEEDING APPARATUS Filed Aug. 24, 1962 v 4 Sheets-Sheet 4 AUSTIN S.CHA IQ DLER R AgMoND A. LABOMBARDE P PM ATTORNEYS United States Patent3,148,876 SHEET FEEDING APPARATUS Austin S. Chandler, Fitchburg, Mass.,and Raymond A.

Lahomharde, Nashua, N.H., assignors to The International Paper BoxMachine Company, Nashua, N.H.,

a corporation of New Hampshire 7 Filed Aug. 24, 1962, Ser. No. 219,30713 Claims. (Cl. 271-12) This invention relates to sheet feedingapparatus of the type having a rotating feed roll with suction aperturesfor segregating the end sheet from a magazine and moving the sheet alonga path. It especially relates to such apparatus capable of feeding flatsheets, having a smooth coated surface, rather than a rough fibroussurface, at relatively high speeds such as five hundred to one thousandsheets per minute, without malfunction.

Sheet feeding mechanism has heretofore been proposed in which aninclined, end-feed magazine feeds each successive endmost sheet intocontact with the face of a suction feed roll, the suction apertures inthe face of the roll gripping the leading edge portion of the end sheetand sliding the sheet through the magazine gate way. For example, in US.Patent 2,251,945 to Labombarde of August 12, 1941, the leading edgeportion of the end sheet is pressed against the face of the roll toassume the curve of the roll, and then carried around the roll betweenthe roll face and a curved stretch of an endthe pressure of the endmostsheet against the face of the roll or to double feed because of frictionbetween the end sheet and the next succeeding sheet.

In this invention, because of the difficulty of accurately feedingsmooth coated sheets, at the desired speed, individually andsuccessively from a stack, the necessity for maintaining completecontrol of each sheet as it is car ried around the roll face and thenecessity for positively stripping the sheet from the roll to deliver itto registering mechanism, the structures of the prior art have beenconsiderably improved. The magazine of the invention is so mounted thatthe sheets are supported on a lower edge in nearly vertical position toreduce sheet friction. A portion of the face of the endmost sheet,intermediate of the height of the sheet, is pressed into tangentialcontact with the smooth face of the suction feed roll by power operatedindex means so that the leading edge portion of the sheet is spaced fromthe face of the roll. The magazine gate is a barrier for the leadingedge of the endmost sheet, when the sheet is in its normal flat plane,but suction from the feed roll draws the leading edge portion out of theplane of the sheet against the face of the roll into a position oppositethe gateway of the magazine. The application of maximum suction is madesubstantially instantaneous by the provision of a wide suction portcommunicating with even wider suction apertures in the roll face, thelatter being nearly as wide as the face itself, whereby the leading edgeportion of each endmost sheet is positively bent away from the nextsucceeding sheet to reduce friction and is then carried through thegateway. A stripper belt trained around a groove in the face of the rollpositively strips each sheet from the roll, while traveling at the samesurface speed, to avoid marking the coating on the sheet.

The principal object of the invention is, therefore, to

provide an improved sheet feeding apparatus, of the su'c-' roll feedwhich bends the gripped portion of a sheet out of the plane of thesheetand into alignment with a magazine gateway, or sheet passage, therebyassuring single feed, breaking frictional contact with the next succeed'ing sheet and bending only thesheet being fed.

A further object of the invention is to provide stripping means notdependent on suction, release of suction, stationary blades or the like,but comprising a belt traveling at the same surface speed as the speedof the roll face and preferably inset in a groove in the roll face.

Still another object of the invention is to provide a novel indexingmeans foradvancing a horizontal stack of substantially vertical sheetsup to the face of a'suction feed roll with the endmost sheetpressedagainst the roll face at a predetermined pressure.

Other objects and advantages of the invention will be apparent from theclaims, the description of the drawings and from the drawings in which:

FIG. 1 is a side elevation of sheet feeding apparatus constructed inaccordance with the invention,

FIG. 2 is a plan view thereof,

FIG. 3 is an enlarged side elevation, in section on line 33, of FIG. 2,

FIG. 4 is an enlarged end elevation, in section on line 4-4, of FIG. 3,

FIG. 5 is a somewhat diagrammatic sectional view similar to FIG. 3showing the feed action of the device on a still further enlargedscale,,

FIG. 6 is a diagrammatic perspective view of the rotating feed roll ofthe invention, partly in section, and

FIG. 7 is a view similar to FIG. 6 of t the stationary suction drum.andtransverse suction port of the invention. 1

As shown in thedrawings, the sheet. feeding apparatus 30 of theinvention includes a main frame 31 having an electric motor 32, mountedon a carriage 33 movable on threaded rods 34 by a handle 35 foradjusting the tension of drive chain 36. v V I A stationary,cylindrical, suction drum 37 extends across the main frame 31, thehollow interior 38 of the drum being connected by the fluid conduit 39to a suit able sourceof suction, not shown, such as mill suction,suction pump and tank or the like. The interior face 41 of the rotatablefeed roll 42 is adapted to revolve aroundthe smooth exterior face 43 ofthestationary drum 37, a-roll gear 44 being intermeshed with a gear 45carried by a shaft 46 and the shaft 46 being driven by the .motordrivechain 36. i

Asbest shown in FIGURES 4:and 6 the circumferential face 47 of the feedroll 42 is smooth and provided with at least one transverse suctionaperture 48. Preferably, however, there are a: plurality of such suctionapertures spaced circumeferentially around the face 47, for example six,as shown. Each aperture 48 comprises a pair of laterally spaced, radialpassages, or bores, 50 and 51 joined at the inside by a lateral passage52 and each terminating at the outside in one of two pairs 53 and 54 ofshallow, tapered, transversely extending grooves, such as 55 and 56. Thesmooth face 47 of feed roll 42. preferably includes a central, shallow,circum ferential groove 57, for a purpose to be described hereinafter.Each suction aperture 48 forms a pair ofsuction mouths 58and 59 in thesmoothface 47 of feed. roll 42 each on an opposite sideof thecircumferential groove 57 and each extending from proximate groove 57 toproximate the adjacent side 61 or 62 of the face 47.

' The suction control mechanism 63 includes the source of suction, theconduit 39 and suction drum 37, drum 37 liavinga novel suction port 64located near the gateway of the magazine 65. It has been found that thearea and width of the suction aperture 48 and the rapidity with whichsuction is applied thereto are critical in the feeding of sheets at highspeed from a magazine and especially so when the sheets are smoothcoated. The suction aperture 48 is thus of relatively large area andnearly as wide as the face, 47 whereby a suction grip is secured acrosssubstantially the full width of the sheet.

If the suction port 64 was relatively narrow or if it was circular inconfiuration, the inside of aperture 43 might pass by the port withoutcommunicating sufficient suction, or with a slow gradual communicationof suction, to the mouths 58 and 59 thereby failing to grip and feed theendmost sheet 71 of magazine 65. Suetion port 64 is, thereforerelatively wide and preferably in the form of an inverted T, the head 67of the T forming a wide, laterally extending slot and the stem 68 of theT extending circumferentially in the direction of feed for apredetermined distance.

As best shown in FIG. 4, the special configuration of suction port 64and of suction aperture 48 results in the creation of a wide zone ofcommunication, indicated at 69 in FIG. 4, the instant that each passage52 rotates around drum 37 to partially expose and communicate with thewide head 67 of the port 64. When the mouths S and 59 have sucked, or.drawn a sheet 66 onto the face 47 of roll 42, maximum suction is nolonger required and the stem 68 of the port 64 is adequate communicationto aperture 48 until suction is broken at the terminal end 76 of thestem.

The magazine 65 is of the end feed type with the stack 73 of identicalsheets 66, supported generally horizontally and with each sheet 66upstanding vertically on its lower edge 74. Friction between thecontacting faces of the sheets 66 is thus reduced to prevent adhesionthereof and to prevent double or triple feeding.

Each endmost sheet 71 is normally in a flat plane with the leading edgeportion 75 spaced at a predetermined distance from the face 47 of roll42 and with an intermediate portion 76 of the exposed face 77, just inadvance of the leading edge portion 75, in tangential radial contactwith roll face 47. The roll face 47 thus forms a movable end wall formagazine 65 but its rotary motion is not imparted to each successive endsheet 71 because the face 47 is of smooth metal and the exposed face 77is smoothly coated.

In conventional magazines a movable gate is usually positioned to form agateway, or sheet passage, directly opposite the leading edge of eachendmost sheet for pass ing one sheet at a time. In the apparatus of thisinvention the movable gate 78 is adjustably pivoted at 79 but ispositioned-in the path of the leading edge of each endmost sheet 71, ifthe sheet were slid off the stack 73. The gate 78 forms a gateway 81with the face 47 of roll 42 which requires each endmost sheet to be bentout of its normal flat plane by the suction from mouths 58 and 59 beforetheleading edge portion can pass through the gateway. Thus the leadingedge portion 75 of each'endrnost sheet is drawn toward the face .47, andaway from frictional contact with the next succeeding sheet, which isstill opposed by gate 78, and the endmost sheet is then Withdrawn fromthe stack by the rotation of, and adhereance to, thesuction feed' roll42. Misfeed is'prevented by the rapid application of suction over a widearea produced by suction port 64 and double feed is prevented by bendingeach sheet out of its flat plane before slidably withdrawing the sheetfrom the stack.

Magazine 65 includes power actuated feed mechanism- 82, the feedmechanism '82 including an endless carrier extending along the entirebottom to beyond the gateway of the magazine preferably in the form of apair of parallel, endless chains 83 and 84. Chains 83 and 84 are trainedaround sprockets such'ias 85 and 86 with the upper stretches 87 and 88of the chains supporting the stack 73. The upper stretches 87 and 88 areindexed toward the face 47 of feed roll 42 by a ratchet and pawlsynchronized with the speed of rotation of feed roll 42;

Magazine 65 includes the subframe 94 supported at a slight incline fromthe horizontal, to eliminate the need for a movable back plate bearingagainst stack 73, and carried by a pair of posts such as 95 slidablyadjustable in brackets such as 96. Subframe 94 includes cross rods 97carrying side wall brackets 98 and 99, the brackets 98 and 99 beinglaterally adjustable by the threaded cross rods 102. The brackets 98 and99 include slots such as 163 for the set screws 104 of side wall plates105 and 106 whereby the height of the magazine walls may be varied aswell as the width thereof. A threaded cross rod 107 is provided forlateral adjustment of the spacing between the chains 83 and 84, thesprockets 85 and 86 benig journalled to an elongated chain plate 108 and199 threaded. on the cross rod 107.

A traveling belt conveyor 112 is provided to hold each successive sheet66 against the face 47 of roll 42 after segregation of the leading edgeportion 75 thereof by roll 42, to assist in withdrawing the remainder ofthe sheet from the stack and to form the outside of a sheet path leadingaway from roll 42. As shown, conveyor 112 includes an endless belt 113trained around a pulley 114 located just in rear of gateway 81, at oneend and trained i which carries pulley 114, the arm 119 having anextension 121 for carrying the pivotable magazine gate 78. Belt 113 thusincludes the curved stretch 122 which forms the outside of thesheet patharound roll 42 and the straight stretch 123 which also forms part of theoutside of the sheet path. The stretches 122 and 123 advance at the samesurface speed as the surface speed offace 47 andare preferably of softfriction material, such as rubber, to avoid marking the outside face 124of each sheet 66 while advancing with, and bearing against, the samewith a predetermined pressure. 7

The traveling belt stripper assures that each successive, individualsheet 66 segregated from stack 73, through gateway 81, will bepositively stripped from suction feed roll 42 Without marking theexposed face 77, without sending the leading edge portion 75 and withcomplete control of the sheet from the magazine to the registrationconveyor 116.

Stripper 136 includes the endless belt 131 trained around the suctionfeed roll 42, within the circumferential groove 57, and around thepulley 132 which is located away from roll 42 and well beyond theentrance of registration conveyor 116. Belt 131 includes the curvedstretch 133 extending around roll 42 and the straight stretch 134, bothforming the inside of the sheet path and paralleling the correspondingstretches of the conveyor, belt 113. A tension pulley 135 is providedfor maintain ing the straight stretch 134 in taut condition and belt 131is preferably of friction material such as rubber. The depth of groove57 and the thickness of belt 131 is such that the outer face 136 of thebelt is just below the level of the smooth circumferential face 47 ofroll 42 whereby the curved stretch 133, although passing by the exposedface 77 of each endmost sheet, and passing by gateway 81, has no contactwith the face 77 and no tendency to impart motion thereto. 7

In operation the magazine 65 indexes the stack 73 toward the smooth rollface 47 to press the intermediate portion 76 of each successive endmostsheet 71 tangentially against the face 47, while the gate 78 preventsthe segregation of the normally flat endmost sheet. As each suctionaperture 48 rotates to a position opposite gateway 81 it comes intorapid communication with suction port 64 to exert maximum suction on theleading edge portion 75 of each endmost sheet. The suction exerted,curves the leading edge portion 75 away from the next succeeding sheet,draws it against the smooth face 47 and closes the mouths 58 and 59.With the portion 75 gripped and adhered to face 47, the continuedangular advance of the roll 42 withdraws the remainder of the endmostsheet from the magazine with the sheet coming between the curvedstretches 122 and 133 of the belt conveyor and stripper. The sheet isthen under control of the conveyor and stripper as the apertures 48rotate beyond the stem 68 of port 64 to break the suction. The stripper130 positively peels the sheet from the roll and with the conveyor 112,advances the sheet further along the sheet path to be received by theregistration conveyor 116 or any other suitable apparatus.

Registration conveyor 116 is of the chain lug type with parallelhorizontal endless chains 140 and 141 driven in timed relation with theapparatus 30 by the drive connection 152. It forms no part of thisinvention and is included only to show that the sheet path of theapparatus 30 overlaps the entrance of the next succeeding treatmentdevice or carrier in order to deliver sheets thereto under completecontrol.

We claim:

1. Sheet feeding apparatus of the type having a sheet magazine and arotatable sheet feed roll, said apparatus comprising magazine means forholding a plurality of' fiat, planar, smooth faced sheets with theintermediate portion of the exposed face of the endmost sheet intangential engagement with said roll and with the leading edge portionof said endmost sheet spaced at a predetermined distance from said roll;a smooth, circumferential face on said roll, incapable of impartingrotary motion to said endmost sheet, said smooth face having at leastone transverse suction aperture therein adapted, when suction is appliedthereto, to curve said leading edge portion out of its flat plane intoengagement with said smooth face, grip said portion and impart rotarymotion to segregate said sheet from said magazine; a 'travelingbeltconveyor having a curved stretch bearing against the face of said roll,said conveyor extending from said magazine to a substantial distancebeyond said roll to form the outside of a sheet path; a traveling beltstripper having a curved stretch in a plane below the plane of thesmooth circumferential face of said roll, said stripper belt parallelingsaid conveyor belt to form the inside of said sheet path for guidingeach sheet segregated from said magazine away from said roll and suctioncontrol mechanism including an elongated transverse suction port fixedwithin said roll to communicate with said suction aperture for rapidlyapplying maximum suction thereto when said aperture rotates to aposition opposite the said leading edge portion of each successiveendmost sheet in said magazine.

2. Apparatus as specified in claim 1 wherein said face includes acircumferential groove and said traveling belt stripper is trainedaround said roll within said groove.

3. Apparatus as specified in claim 1 wherein said face includesacircumferential groove in the central portion thereof, said travellingbelt stripper is trained around said roll in said groove and the mouthof said suction aperture extends on each opposite side of said groovesubstantially to the opposite sides of said face.

4. Apparatus as specified in claim 1 wherein said magazine includes anendless carrier for supporting the sheets therein and power operatedmeans urging said carrier in the direction of the face of said roll andpressing said intermediate portion of the exposed face of eachsuccessive endmost sheet thereagainst, said intermediate portion beingjust in advance of said leading edge portion of said sheet.

5. Apparatus as specified in claim 1 wherein said traveling beltconveyor is of friction material for frictionally engaging the outersurface of each sheet segregated from said magazine and completing thewithdrawal of said sheet from said magazine in cooperation with the saidsmooth circumferential face of said roll.

6. Apparatus as specified in claim 1 wherein said magazine includes feedmechanism supporting said sheets upstanding on the lower edges thereofto reduce friction between adjacent sheets, said mechanism presentingeach successive endmost sheet to the face of said roll with the upperedge portion forming said leading edge portion spaced from said rollface and with said intermediate portion just below and proximate saidupper edge portion whereby said smooth face forms a movable end wall onsaid magazine just in advance of said leading edge portion.

7. Apparatus as specified in claim 1 wherein the face of said roll is ofmetal and forms a smooth, metal, a movable end wall for said magazine,tangentially contacting a portion of the exposed face of each successiveendmost sheet in said magazine intermediate of the height of said sheet,saidmagazine includes a gate for opposing the sliding segregation of theleading edge of said sheet and said magazine includes a gateway forpassing said leading edge when said leading edge is curved out of theplane of said sheet by suction exerted through said transverse suctionaperture.

8. 1n apparatus of the type having a rotating feed roll with atransverse suction aperture for segregating a plurality of fiat sheetsindividually and successively through the gateway of a magazine holdinga stack of said sheets; the combination of a smooth circumferential faceon said roll having a circumferential groove therearound; poweractuated, magazine feed mechanism, including an endless carriersupporting said stack of sheets and advancing toward the face of saidroll to press an intermediate portion of the exposed face of eachsuccessive endmost sheet into tangential engagement with the smoothcircumferential face thereof and to space the leading edge portion ofsaid sheet from said face; suction control mechanism including atransverse suction port within said roll, substantially coextensive intransverse dimension with said suction aperture, for rapidlycommunicating suction thereto when said aperture has rotated to just inadvance of the gateway of said magazine exactly opposite to the saidleading edge portion; a traveling belt conveyor extending from just inrear of the gateway of said magazine to beyond said roll, said conveyorhaving a curved stretch hearing against said smooth, circumferentialface, and a traveling belt stripper having a curved stretch trainedaround said roll within said circumferential groove, said belt strippercooperating with said belt conveyor to guide each successive sheet awayfrom said roll.

9. Apparatus as specified in claim 8 wherein the endless carrier of saidmagazine feed mechanism comprises a pair of laterally spaced, generallyhorizontal, chains supporting said sheets on the upper stretchesthereof, said upper stretches being indexed toward the face of said rollby power connection with said rotating feed roll and extending along theentire bottom to beyond the gateway of the magazine.

10. Apparatus as specified in claim 8 wherein said transverse suctionport is the head of an inverted T shaped opening, the stem of the Toverlapping the curved stretch of said endless belt conveyor formaintaining suction in the apertures in the face of said roll until asheet has been gripped by said stretch and for then breaking saidsuction.

11. Apparatus as specified in claim 8 wherein each said suction aperturein the face of said roll includes two pairs of circumferentially spaced,shallow, suction mouths, each pair on an opposite side of thecircumferential groove in said face, the shallow mouths of each pairextending transversely from proximate said circumferential groove toproximate the adjacent side edge of said face.

12. Apparatus for feeding a plurality of flat, smooth sheetsindividually and successively along a path, said apparatus comprising arotatable feed roll having a smooth circumferential face ofpredetermined length substantially greater than the correspondingdimension of a sheet to be fed thereby, said face having a plurality oftransverse suction apertures spaced therearound; drive means forrotating said roll at a predetermined surface speed to advance saidsuction apertures along a curved stretch of said path; power actuatedmagazine feed means mounted along said curved stretch and pressing anintermediate portion of the exposed fiat face of successive endmostsheets therein tangentially against the circumferential face of saidroll with the leading edge portion thereof spaced at a predetermineddistance from the circumferential face of said roll; suction controlmechanism rapidly creating maximum suction in each said suctionaperture; at said magazine means, gripping said leading edge portion ofeach said endmost' sheet, curving said portion out of the plane of thesheet and advancing said sheet along said curved stretch; an endlessstripper belt associated with, and traveling at the same surface speedas that of, said face for guiding the leading edge portion of eachsheet, fed along said curved stretch, tangentially into. a straightstretch of said path leading to a registration conveyor; a travelingbelt conveyor having a curved stretch extending from said'magazine meansaround said smooth circumferential face and bearing thereagainst forfrictionally engaging and retaining said sheets on said face aftersegregation thereof and guiding the same to said registration conveyor,said registration conveyor, synchronized withsaid drive means and saidcontrolmechanism, said conveyor having register elements extending alongsaid straight stretch and adapted to continue the advance along saidpath of each successive sheet received from said stripper belt.

13. Sheet feeding apparatus comprising a rotatable cylindrical feed rollhaving a smooth circumferential face; an automatic end feed sheetmagazine pressing an intermediate portion of the exposed face of eachendmost sheet therein, into tangential engagement with said smooth faceand spacing the leading edge portion thereof from said smooth face;suction means on said roll to curve said leading edge portion of theexposed face of theendmost sheet out of the plane of the sheet, drawsaid portion into contact with said smooth face and segregate saidsheettherefrom; a traveling friction belt conveyor having a curved stretchbearing against the face of said roll, said conveyor extending from saidmagazine to a substantial distance beyond said roll to form the outsideof a sheet path; a traveling friction belt stripper having a curvedstretch inset into the face of said roll, said stripper paralleling saidconveyor to form the inside of said sheet path, beyond said magazine andsuction control mechanism for rapidly applying maximum suction to saidsuction means, to positively grip each sheet, maintain said suctionuntil said sheet is well Within said path and then break said suction.

References Cited in the file of this patent UNITED STATES PATENTS

1. SHEET FEEDING APPARATUS OF THE TYPE HAVING A SHEET MAGAZINE AND AROTATABLE SHEET FEED ROLL, SAID APPARATUS COMPRISING MAGAZINE MEANS FORHOLDING A PLURALITY OF FLAT, PLANAR, SMOOTH FACED SHEETS WITH THEINTERMEDIATE PORTION OF THE EXPOSED FACE OF THE ENDMOST SHEET INTANGENTIAL ENGAGEMENT WITH SAID ROLL AND WITH THE LEADING EDGE PORTIONOF SAID ENDMOST SHEET SPACED AT A PREDETERMINED DISTANCE FROM SAID ROLL;A SMOOTH, CIRCUMFERENTIAL FACE ON SAID ROLL, INCAPABLE OF IMPARTINGROTARY MOTION TO SAID ENDMOST SHEET, SAID SMOOTH FACE HAVING AT LEASTONE TRANSVERSE SUCTION APERTURE THEREIN ADAPTED, WHEN SUCTION IS APPLIEDTHERETO, TO CURVE SAID LEADING EDGE PORTION OUT OF ITS FLAT PLANE INTOENGAGEMENT WITH SAID SMOOTH FACE, GRIP SAID PORTION AND IMPART ROTARYMOTION TO SEGREGATE SAID SHEET FROM SAID MAGAZINE; A TRAVELING BELTCONVEYOR HAVING A CURVED STRETCH BEARING AGAINST THE FACE OF SAID ROLL,SAID CONVEYOR EXTENDING FROM SAID MAGAZINE TO A SUBSTANTIAL DISTANCEBEYOND SAID ROLL TO FORM THE OUTSIDE OF A SHEET PATH; A TRAVELING BELTSTRIPPER HAVING A CURVED STRETCH IN A PLANE BELOW THE PLANE OF THESMOOTH CIRCUMFERENTIAL FACE OF SAID ROLL, SAID STRIPPER BELT PARALLELINGSAID CONVEYOR BELT TO FORM THE INSIDE OF SAID SHEET PATH FOR GUIDINGEACH SHEET SEGREGATED FROM SAID MAGAZINE AWAY FROM SAID ROLL AND SUCTIONCONTROL MECHANISM INCLUDING AN ELONGATED TRANSVERSE SUCTION PORT FIXEDWITHIN SAID ROLL TO COMMUNICATE WITH SAID SUCTION APERTURE FOR RAPIDLYAPPLYING MAXIMUM SUCTION THERETO WHEN SAID APERTURE ROTATES TO APOSITION OPPOSITE THE SAID LEADING EDGE PORTION OF EACH SUCCESSIVEENDMOST SHEET IN SAID MAGAZINE.